<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <script type="text/javascript" src="../script/jquery-3.6.0.min.js"></script>
  <script type="text/javascript">
    window.onload=function () {
      var $username = $("#username");
      alert("$username value= " + $username.val())
      // var username = $username[0];
      // alert(username)

      var newVar = $username.get(0);
      alert(newVar)
    }
  </script>
</head>
<body>
用户名 <input type="text" id="username" name="username" value="韩顺平教育"/>
</body>
</html>
